Foods with textural contrast, such as baked snacks with a filling, can be appealing to a broad spectrum of consumers. These dual texture foods may include a crispy or dough component, such as a cracker, and a filling component, such as a soft and creamy, shelf-stable sweet or savory filling. Typically, the filling component may exhibit the desired creamy texture from particles dispersed in a lipid and/or aqueous continuous phase. However, such fillings tend to have the shortcoming that the dispersion structure can be thermally destabilized in some instances, such as exposure to baking temperatures, leading to spreading, boiling, and/or oiling-out upon heating. While not wishing to be limited by theory, it is believed that such thermal destabilization may be the result of aggregation of particles leading to lipid separation from other filling ingredients. Thus, such shortcoming renders manufacture of the dual texture snack challenging because the thermal exposure of the filling often needs to be carefully controlled.
In general, three approaches have been used to manufacture such dual texture snacks. By one approach, the crispy or cracker component, which is usually obtained from a dough, can be baked prior to applying the filling. By using such approach, the filling is not exposed to baking temperatures, and the shortcoming discussed above can be minimized or avoided. However, this approach can have limitations in terms of processing and limit product configurations to sandwich-type or other open ended and closed products where the filling can be easily applied after baking. Another approach is to prepare a filled dough with the filling component applied/injected therein prior to baking and then baking the dough and the filling together. A third approach is cooking/extruding a dough casing at high temperatures, pressure, and shear conditions while injecting the filling at the die to co-extrude filled snacks. As mentioned above, these last two approaches are limited by the thermal instability of the filling component at baking temperatures, such as temperatures of about 250° F. or higher, commonly used to bake crackers, chips, biscuits, and the like. When prior filling components are exposed to such baking temperatures, it can suffer from product defects such as filling spreading and oozing out, boiling-out, oiling-out, loss of smoothness, and discoloration.
Prior filling compositions have generally been formulated as aqueous or water-based systems containing an aqueous/hydrophilic liquid continuous phase as an oil-in-water emulsion combined with relatively high amounts of water activity (Aw) lowering humectants (e.g., polyols, glycerine, sugars, syrups, and the like), thickeners, and/or gelling agents (e.g., hydrocolloids, proteins, starches, and the like) to improve thermal stability. These prior fillings, however, are generally unacceptable from an organoleptic standpoint because they can be syrupy or gummy in texture and can often be undesired as a creamy, savory filling (such as a cheese-based filling) due to unwanted sweetness and/or unpleasant aftertaste resulting from the use of humectants such as glycerine.
One typical example of a cheese filling based on the prior creamy fillings is an oil-in-water emulsion composition. Such fillings have a continuous water phase in which the oil phase is dispersed. In this prior filling, the water or hydrophilic phase is mainly made of glycerol (or other polyhydric alcohols), polydextrose syrup, corn syrup, and mixtures thereof. Such construction of these emulsion fillings may be generally stable at low temperatures, but under baking conditions the fillings are typically prone to boil-out or bleed-oil as the lipid phase can potentially undergo coalescence resulting in phase separation or inversion. In addition, the water may also escape from the filling at baking temperatures resulting in blow-out of the dough or unwanted large voids. These prior liquid-liquid emulsions also tend to be interfacially dynamic and their stability can be highly sensitive to shear, processing (e.g., extrusion, etc.), handling, and storage conditions.
Attempts to prepare creamy, emulsion-based fillings that are bake-stable typically included additional components that compromise other qualities. For example, prior creamy filling include gelling agents (such as whey protein), thickeners, humectants (such as glycerine), polyols or other additional ingredients to improve stability, but such ingredients can compromise desired organoleptic qualities that may alter the desired taste, texture, and/or flavor of the filling or otherwise lessen the eating experience. In some cases, high amounts of these ingredients can impart an undesirable aftertaste (such as bitterness or a burning sensation from glycerols), which can be especially pronounced in salty or savory fillings. With high amounts of glycerine or glycerol, which can also impart additional sweetness to the filling, prior savory bake stable fillings may also require the use of flavor modifiers (e.g., lactisol syrup) to suppress undesired sweetness provided by the glycerol. Such additional use of gums, humectants, glycerine, thickeners, polyols, and flavor masking ingredients can be undesired in many cases.
In yet other instances, baked filled snack products may employ the use of peanut-based or other nut-based ingredients as a component of the food filling. While such fillings may be described as heat or bake stable, they use peanut or other nut or bean based ingredients in the filling. Peanut and nut or bean based ingredients are less desired by many consumers.